


Parsimony

by MlleMusketeer



Series: Mirrorverse [1]
Category: Transformers: Prime, Transformers: Shattered Glass
Genre: Bodyswap, Dimension Travel, Escape, Espionage, Evil Twins, Groundbridge Accident, Implied/Referenced Abortion, Kidnapping, M/M, Medical Torture, Mentioned Dubcon, Shattered Glass
Language: English
Status: Completed
Published: 2014-01-27
Updated: 2014-04-17
Packaged: 2018-01-10 05:23:02
Rating: Mature
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 23
Words: 18,400
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1155603
Author URL: https://archiveofourown.org/users/MlleMusketeer/pseuds/MlleMusketeer
Summary: <blockquote class="userstuff">
              <p>A groundbridge accident strands Ratchet in an unfamiliar body in a world that is frighteningly familiar...and terrifyingly different. A misstep will mean death, still more so when Ratchet realizes that his 'accident' was anything but, and that the world he loves is in terrible danger.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> Everyone else was writing Shattered Glass fics, and I got inspired and wrote most of this in one night. Oops?

Ratchet woke to the sting of a fresh weld and red optics. He started back against the berth, seeking for battle protocols through the haze of a rebooting processor. 

“Relax, Ratchet,” said Optimus. “I have finished the repair.”

Ratchet blinked rapidly, trying to reset his optics without reaching for the medical codes to do it forcibly—the profile was Optimus, but the color was wrong. His optics were red, his helm black, the familiar broad shoulders deep purple. Processor damage, most likely; he must have sustained an injury to his optical suite.

“Thank you,” he said, shakily. Something else was off; Optimus’s field was hardly present at all, clamped in tight under his armor. He sat up. Optimus did not try to stop him. “What happened?”

“What happened? You were the one who set the groundbridge, Ratchet. Whatever glitched with it? Was _your_ fault.” That was Arcee. His optics were still malfunctioning; her plating was dark purple, almost black. Ratchet decided enough was enough and engaged the medical overrides to force-reset his optical suite. 

His vision frizzed into static, then came back online. He blinked again, shook his helm—and stared. 

Nothing had changed. 

And his self-diagnostic had come up almost completely clean, save for a minor tear in the plating on one arm.

“Well? Got anything ya wanna explain, Doc?” said Wheeljack. He looked much the same, though gray and purple where there should have been red and green. The Autobrand on his chest, too, was purple, and Ratchet thought uncomfortably of Megatron. 

“Enough,” said Optimus, a vicious note in his voice Ratchet had never heard before. He glanced up at Optimus, the surprise flaring in his field, and Optimus _smirked_. “Whatever miscalculation Ratchet made, I am sure that it will not be repeated.” 

There was a threat in the way that he said it, the deliberate tilt of his helm as he looked down at Ratchet and Ratchet hastily reset his vocalizer and bobbed his helm in a nod. He pulled his field in before it could betray him again. “Of course,” he said, not sure what else to say. “I’ll go check it now.”

“Good. In the meantime, Wheeljack and I are going to make ourselves actually _useful_ , or as useful as we can be, given that _someone_ fragged up the groundbridge.”

“I said _enough_ ,” said Optimus, calm and quiet. His field flared out, sharp and precise as a scalpel, and Arcee flinched, winglets going down. 

“Yes sir,” she said, and without another word transformed and vanished down the hall leading out of the base. Wheeljack sloped insolently after her.

Ratchet remained frozen. Optimus had never in all their time together used his field as a weapon, much less something to punish those under his command. And the slight brush of it that he’d felt was all wrong, completely and utterly _wrong_. 

Movement behind him made him turn to look up at Optimus, taking an involuntary step backward as he did. “Optimus—”

“I am not interested in excuses, Doctor,” said Optimus. “Repair the groundbridge, and ensure that this does not occur again.”

“Understood,” said Ratchet. He made his way over to the groundbridge, somewhat unsteadily. Optimus did not move. 

“Is there anything else?” Ratchet asked at last.

“Your familiarity is wearing,” said Optimus. “See that it does not continue to be so.”

Ratchet opened his mouth, and Optimus’s field flared out and lashed over his. He hunched his shoulders and repressed the yelp that tried to claw its way out of his vocalizer.

Optimus was still there, waiting. 

“Yes sir,” Ratchet managed at last, the words strange on his glossa. He kept his optics fixed on the groundbridge controls, not daring to look up and let Optimus see his expression. His hands trembled on either side of the panel. 

At long last, the sound of retreating pedes announced that Optimus was leaving. Ratchet didn’t move, staring down at the panel without seeing what was written on the readout. 

It was the shock rather than the pain, the shock and the fear. Whatever that...that _thing_ was, it wasn’t Optimus. It couldn’t be. Optimus would _never._

He already had a long list of things that Optimus would never do that this Optimus had, and he’d been online for barely ten minutes. But even knowing that did little to assuage the hurt of suddenly hearing a threat in that beloved voice, feeling a field so like Optimus’s used against him. 

_Think_ , he told himself, as his hands moved over the bridge controls, a diagnostic so familiar he could do it even now. _Be logical. What is the parsimonious explanation? Not a malfunction with my own systems; Optimus’s behavior precludes that. Neither does his behavior indicate the involvement of Synth-En; he also lacks the distinctive green optics._

He reached under the groundbridge panel to make a few other connections. _The groundbridge is severely miscallibrated. Perhaps that has to do with—_

“By the Allspark.” He said it out loud, and withdrew his hand. He ran through the things he’d reset; all of them were very unlikely to be coincidental, as it would be extremely difficult to break so many different components _just so_. “Frag.” 

It had to be deliberate.

Someone had tampered with this groundbridge for a reason. Someone had done so extensively, a dangerous project, particularly dangerous with the thing that wore Optimus’s frame looking over their shoulder. It had to be a slagged good reason. 

He put both hands on the controls and looked down at them. 

And flinched back, because the arms weren’t his. 

Or rather, they were, but the wrong color. Energon-blue ran up across his forearms, over his doors and torso. “No, oh no…” 

His plating started to rattle. He clamped it down hard against his frame to keep quiet—Primus forbid that Optimus came back to see what was making noise—and went back to work. 

There was more than groundbridge sabotage here. A lot more, and he had to have the time to go through the database, had to see if whoever it had been had left notes. He had a suspicion now, but that was going to wait until he had time to run a full self-diagnostic and go through the base’s records. It was the most parsimonious explanation.  That didn’t mean it was right.

He worked fast. He had no desire to run into Bumblebee or Bulkhead, and he didn’t want this Optimus to get any more impatient. He had to stay quiet, under the radar, until he could do something about this. 

Slag this would be so much easier if his hands weren’t shaking!


	2. Chapter 2

Ratchet retreated into his lab and closed the door with the relief of a hunted thing. He leaned against it, shuttered his optics. Thank Primus. Some privacy.

He’d encountered Optimus in the hallway. The larger mech had stopped him with a hand on the shoulder—Primus, he’d never thought he’d see the day when _that_ gesture became threatening!—and asked in a very calm and genteel tone which was nevertheless filled with menace if the groundbridge was functional. 

“Yes,” Ratchet had said. “I’m hoping to find out what happened by going through the logs. Sir.”

He’d tried to move. The hand had kept him in place as Optimus scrutinized him. He’d started shaking again. Optimus made no sign of acknowledgement, but at last nodded and released him.

At least Optimus and this Ratchet didn’t seem to share an intimate relationship. There was too much suspicion on Optimus’s part, as if he expected Ratchet to be actively working against him. As if he expected Ratchet to behave like Starscream.

Well. Ratchet had played along long enough. It was about time the world gave him an explanation. 

With that in processor, he started toward the computer, only to step back and flatten himself against the door with battle protocols whining to life as something jerked and clattered and screeched from the medical berth.

There was a cabinet between him and the berth, and so he couldn’t see what exactly was making the racket, but it wasn’t coming any closer. He relaxed, glanced down at his hands, and froze again. 

No scalpels. A saw and a drill, and were those miniaturized _blasters_ on the dorsal surfaces of his arms?

He’d started shaking again. He was getting tired of that.

He forced the battle protocols offline, and let out a heavy ventilation as the blasters slid back into concealment. That self-diagnostic was getting more and more urgent. 

But first, there was the small matter of whatever was behind that cabinet. 

Ratchet stepped away from the door and moved (he hoped) purposefully toward the berth. He resisted the urge to transform even one hand into a weapon, because frankly, he didn’t know how to use either of the slagging things. He also certainly _did not_ want to know what this body had instead of an arc welder. 

He rounded the cabinet, and there was a whimper from the berth. A blue-slitted visor turned toward him, flaring white with terror. The Vehicon jerked against his restraints, a dry sob escaping from a sparking, exposed vocalizer.

Ratchet’s spark flared up with rage.

“Who did this?” he demanded, even as his vision was overlaid with diagnostics, diagrams of the parts missing and damaged, the most accessible ganglia to offline pain sensors through. He went for that first, heard the involuntary heavy ventilation of relief. He checked energon lines and to his shock found most of them neatly clamped, a supplemental energon line already inserted into the aortal feed. 

A lot of the damage he found he could simply repair; he’d had enough experience cobbling together repairs from nothing for Optimus. But some parts were simply missing. 

The vocalizer, at least, was in the first category.

“Why?” said the Vehicon, the moment he finished the repairs and turned his attention elsewhere. 

“I’m a doctor,” said Ratchet. “I _repair_ things.”

The Vehicon fell silent again. He was still terrified; Ratchet could feel the flicker and heave of his field. But there was something else, confusion and shock and resignation. 

“I won’t be able to do much more,” said Ratchet at last. “I don’t have the spares to replace the missing parts—”

“That’s because you used them on the Prime,” snarled the Vehicon. “I don’t care what kind of sick game you’re playing this time, _Autobot_. Just fragging _kill_ me!” He jerked against the restraints, subsided with vents heaving. 

Ratchet, who’d been in the act of reaching for a cube of medical energon, froze. “What?”

“You heard me!” There was a sob in the Vehicon’s voice. “Just fragging offline me and have done with it!”

Ratchet very deliberately finished pulling the energon down from the shelf, and made sure his pedes were firmly planted on the ground before he turned back to the Vehicon. “I am not going to offline you,” he said. “Or harm you.”

The Vehicon said nothing. 

A horrible suspicion began to form in Ratchet’s processor. “Oh no.”

The Vehicon glared at him. “Is amnesia a common problem for Autobots, then?”

“Not amnesia,” said Ratchet, hooking the energon to the line with practiced ease and distantly noting that the Vehicon’s paintjob was off as well; a dull metallic red rather than purple. “Worse. Tell me, did this—” he corrected himself, disgusted, “did _I_ have any major projects he—I—was working on?”

The Vehicon was silent, field pulled in tight, utterly unreadable.

Ratchet ventilated heavily again. “I’ll just check the database then. Tell me if you need anything.”

There was something like a muttered curse from behind him. Ratchet pretended to ignore it. 

Gaining access to the database was easier than expected; on impulse he tried his own passwords, and found that they worked. “At least _something_ makes sense,” he muttered, and set about going through the files the previous occupant had left. Among them, he found the records on the Vehicon.

“Odd,” he said out loud. 

The Vehicon shifted; the reflection in the polished cabinets showed it looking at him with what could have been curiosity, but was more likely dread.

“The spark spectra recorded here is all wrong,” he went on. “It doesn’t match yours at all—”

Rage flared from behind him, the field weak but the intensity of the anger perfectly clear. Ratchet turned to look at the Vehicon, who immediately tucked in his field and flinched back against the berth. 

“What happened?” Ratchet said. 

“You don’t remember?” the Vehicon spat, and then hesitated. His helm tilted to one side, considering. Then, almost smugly, “You’re not him. Are you?”

Ratchet’s vents chuffed with irritation. “I don’t know what you’re talking about.”

“I wonder how long it’ll be before Prime figures out that you’re impersonating his chief medical officer,” said the Vehicon, and there was outright glee in his voice now. “He might even be glad enough to be informed of such an infiltration to release me.”


	3. Chapter 3

Ratchet stepped back and ran into the lab bench. He opened his mouth. He closed it, lost for words. He felt like someone had just yanked the substrate out from under his tires. 

“He’s supposed to have that honorable streak, isn’t he?” said the Vehicon. “I doubt it’ll apply to _you_ , though. He doesn’t like spies.”

“Perhaps you could cease threatening me and tell me what the _slag_ is going on!” Ratchet snapped, and winced as he realized how loudly he’d said it. 

“Why should I?” said the Vehicon. “I’m a prisoner. I’m already offline, I just haven’t stopped ventilating yet.”

“You’re trying to blackmail me.”

The Vehicon nodded. 

Ratchet let out a heavy ventilation and pinched the nasal ridge of his helm. There wasn’t much he could offer. “I’ll take you with me,” he said, though it went against his very programming to leave anyone in this situation. “When I leave.” _If I leave_ , a small, nasty part of his processor put in, and he tried to ignore it. 

The Vehicon looked at him, speculation in his field. 

“That is as much of a promise as you’re going to get,” Ratchet pointed out. “And I doubt that Optimus will have much use for you if I’m not around. If he’s anything like the Optimus _I_ know, selling someone out for your own benefit won’t sit well with him.”

There was a distinct pause. 

“I suppose that’ll do,” said the Vehicon.

“It will have to. Now that we’re done manipulating each other, how about you tell me what, exactly, happened, and why you seem to know what happened to me when I don’t.”

“The Autobot medic discovered how to exchange sparks and processor data between frames,” said the Vehicon. “This isn’t my frame.”

“Well,” said Ratchet, looking away, “That explains a lot.”

“So who _are_ you?” said the Vehicon. 

“We have more pressing matters,” snapped Ratchet. “Such as how I got here, and who did this.”

The Vehicon was looking at him like he was glitched. 

“What is it?”

“You don’t have to look any further than the frame you’re in to answer that,” said the Vehicon. “The Autobots’ Chief Medical Officer, Ratchet? The Doctor of Doom?”

Ratchet covered his face with a hand. “I am never going to live that one down, am I,” he said to the room at large. “But why would this Ratchet want to impersonate me?”

“I can’t answer that if I don’t know who you are,” the Vehicon pointed out. “Would it help if I started with the introductions?” The sarcasm should have killed the ‘con on the spot.

“Yes,” said Ratchet acidly. “Yes, it would.”

“I’m Crankshaft,” said the Vehicon, very slowly, as if he were talking to someone very stupid. “And you are?”

Ratchet opened his mouth to reply, but the door slid open to reveal Optimus. He froze, yanking in his field again before Optimus could sense his fear. 

“O—Sir,” he said, correcting himself just in time as the crimson optics fixed on him, narrowing as they did. “Is everything all right?”

“I thought I heard a commotion,” said Optimus, looking around. 

“Then I apologize for disturbing you,” said Ratchet quickly. “It was unintentional. A glitch with the prisoner’s life support systems.”

Crankshaft flattened himself against the berth as he received the brunt of Optimus’s attention.

“I thought you said you intended to offline him,” said Optimus mildly.

“There was another assay I wanted to run,” said Ratchet. 

“I see. So you repaired him.”

“It required him somewhat more functional, yes.”

This time there was no warning as Optimus’s field struck him, and he put a hand back to steady himself against the lab bench as Optimus moved forward to inspect Crankshaft. “Experiment quickly, Doctor. He is an unnecessary drain on our supplies.”

“Understood, sir,” said Ratchet. Optimus’s gaze swept back to him, questioning. He didn’t bother to hide the flinch. 

“Clearly you are not yet recovered from this afternoon’s accident,” said Optimus. “I will allow you the requisite time to recover, though I expect a full explanation in the morning.”

And with that, he was gone. Ratchet sagged against the bench. “Does he make a habit of that?” he asked.

Crankshaft nodded. Then, rather shakily, “I think you should be calling him Lord Prime. I never heard Ratchet call him anyone else.”

“Frag,” said Ratchet, weakly, and turned back to the terminal. His hands were trembling again. 

He forced himself into the habitual routine of running a diagnostic, thinking it would suffice to calm him down. He should have known better.

“Is it…” he started, blinked, and stared at the readings. This frame was 20% heavier and 10% larger than his own—the forearms and chest were heavily armored, a far greater percentage of energy routed to the weapons. The percentage of coding concerned with the use of those weapons was shockingly high, and on a purely cosmetic level, the red optics and pointed dentae were more than jarring enough. Ratchet reset his vocalizer. He looked like a nightmare version of himself; the idea of a medic who would do this to himself intentionally…

“So who are you?” said Crankshaft, pointedly.

“Ratchet,” said Ratchet, still staring at the screen. The alt-mode was Cybertronian, not human, and was as nasty a piece of work as he’d ever seen on anyone outside of Lockdown. Worse still, it was recognizably an emergency vehicle. Just…a very nasty one. “ _Not_ this Ratchet. I hypothesize that the groundbridge accident earlier created a rift between dimensions, depositing me here.”

Crankshaft snorted. “Pull the other one, it’s got biolights on.”

“I’d give you a better explanation if I could,” said Ratchet, going back to searching through his counterpart’s files. “But I don’t have one. All I know is that is not the Optimus Prime I pledged—I pledged friendship to.” Frag, he’d almost said, ‘my spark to’ and that wasn’t a good bit of information to let get out, even to a Vehicon in an alternate dimension. Showed how tired he was.

“So you’re Ratchet’s good spark-twin?” 

He repressed the urge to throw something at Crankshaft and said instead, “Something like that. I think. It is the parsimonious explanation, though I do not want to draw a definite conclusion from the limited data available to me now.”

“So, Ratchet’s actually in your universe and you’re here,” said Crankshaft, very slowly and deliberately, in the tones of someone determined to get things clear.

That made Ratchet freeze. “Oh,” he said, as the full implications of that rose horribly in his processor. “Oh no. Optimus.”


	4. Chapter 4

He wouldn’t have chosen this frame if he’d known how _weak_ his counterpart was. 

Ratchet’s lip curled as he looked down at the patterns on his plating. Decepticon-red. Decepticon-blue optics. Weak armoring, and only one set of weapons. His counterpart was pathetic. His laboratory was clean, and Ratchet was willing to bet that the bot didn’t even use it. 

Oh, and everything was crawling with fleshling vermin. Including the false Prime, who had walked in earlier _carrying_ one of them in hand as if it were nothing, a normal occurrence, rather than a perversion of everything his position meant!

And the garish, flashy paintjobs… Ratchet shook his helm. They might as well paint Decepticon decals on themselves. They were a parody of everything the Autobots were supposed to be—the idea of _Optimus Prime_ in bright reds and blues and silvers was wrong on levels Ratchet didn’t have words for. 

But there were useful aspects to this Optimus’s behavior. 

“You should fuel, old friend.”

Ratchet turned, schooling the unfamiliar features into an expression of surprise and pleasant expectation, and accepted the cube of energon that the false Prime pressed into his hands. “Thank you, Optimus.” The name felt strange on his glossa, and it was with an effort that he did not address the false Prime with his Prime’s title. 

“Have you made much progress?”

“Not as much as I’d hoped to.” Ratchet gestured to the computer. “Human machinery is difficult to work with at best.”

“I have every confidence in your abilities,” said Optimus, with a small, charming smile that certainly didn’t belong on a true Prime. A heavy, gentle hand settled on Ratchet’s shoulder, and the false Prime’s field pulsed assurance and love. “Only be careful of yourself, old friend. Your wellbeing is of paramount importance.”

Ratchet sputtered, which made the false Prime smile more, and affection wash over him again. 

He’d been serious, Ratchet realized later, and had to pause in his work on the groundbridge to stifle a chuckle. Absolutely serious. 

Well. There were indeed useful aspects to this foolish, false Prime’s behavior. One of which was, if he’d read Optimus’s field correctly and he certainly had, that the false Prime and his useless little medic were intimate. 

Oh, the possibilities that opened...


	5. Chapter 5

A day had passed, and Ratchet was no closer to finding anything of use than he had been to start with.

And Optimus was watching him, suspicion clear in his behavior if not his field. He would turn around, and Optimus would be there, strange and silent with his field tucked in tight to his frame, unreadable and threatening. Addressing him as ‘Lord Prime’ seemed to placate him somewhat, but not enough. 

Pleading the necessity of research, Ratchet retreated to his laboratory and stayed there as much as possible. Optimus seemed somewhat less inclined to disturb him with that said, though he still had an unsettling habit of appearing every few hours to make quiet inquiries about Ratchet’s progress. Ratchet got good at setting the computer to display a set screen at the stroke of a key, so Optimus did not see what he was actually looking for. 

He hadn’t recharged well the night before, not without Optimus, the gentle hum of his systems and wash of his field, and what little recharge he managed was fraught with ugly dreams. He hoped that Optimus was suspicious enough to keep his counterpart from doing whatever it was he was planning to do. He hoped Optimus would detect something off about the impostor’s behavior, exercise caution. Protect himself before the impostor took advantage of such a weakness.

He didn’t want anyone capable of what had been done to Crankshaft anywhere near Optimus, and he was helpless to do anything about it.

The records of surgeries he found were horrifying. His counterpart had little compunction about inflicting pain, and seemed to view disabling pain sensors as a waste of time. The surgeries that these Autobots had endured made Ratchet’s tank turn in disgust—the replacement of Bumblebee’s t-cog, for instance, had been treated much the same way simple welds were, and those were the things his alternate had done to his own teammates. The Vehicon and Eradicon prisoners who had passed through his hands had fared far, far worse.

Crankshaft was surprised at his horror. It sickened Ratchet that the Vehicon took these atrocities as a fact of life.

Then he’d opened a cabinet and found it filled with the malevolent green glow of Synth-En. 

“What is that doing here?” he snapped, closing it as quickly as he’d opened it. 

“I suppose he was just keeping it around after what happened to Smokescreen,” said Crankshaft.

“What?” Ratchet turned to stare at him. 

Crankshaft shrugged a little. Even he’d agreed that tolerating the restraints was better than Optimus coming in and finding him loose. “Autobots got a new recruit. Next thing you know, Ratchet’s experimenting on him.” His field went somber. “It almost worked. He almost killed Megatron. But something went wrong. He froze, didn’t move. From what Knockout could tell, it burned through his fuel reserves so fast most of his internals warped from the resulting heat dump, and killed him before Megatron even got back to his pedes.”

Ratchet shuddered. “What sort of monster—”

“The same one that created Cybonic Plague, perhaps?” said Crankshaft. 

“Hah. Next you’re going to tell me he invented the cortical psychic patch.”

“As a matter of fact—”

“Don’t,” said Ratchet, raising a hand to forestal further comment. “I don’t want to know.”

He’d started downloading what he could onto a portable drive. If his counterpart had managed to displace Ratchet in the first place, it stood to reason that these Autobots posed a clear danger to Ratchet’s own universe. 

Frag, he was thinking like his Optimus again. 

He thought again of Optimus in the hands of that monster, someone capable of destroying Smokescreen through sheer carelessness, and redoubled his efforts. 

“You know, there is a simpler way to do this,” Crankshaft pointed out. “You could simply download Ratchet’s notes onto that drive and ask Megatron for help.”

“And spend a full day explaining to him that I’m not actually this Ratchet?” said Ratchet. “No thank you.”

“He would listen,” said the Vehicon, with a curious vehemence. “And you’d have me.”

“And what weight would your word carry?”

“More than you think.” 

The conversation ended there. Ratchet went back to work. It’d be a cold day in Pit before he trusted Megatron, even an alternate version of him. Optimus could not afford wasted time.

But it did start to make him pay more attention to Crankshaft, who was, frankly, weird. 

He knew too much, for one thing. The account of Smokescreen’s death was certainly something a Vehicon might have picked up, but he didn’t use titles when referring to the officers, which Ratchet couldn’t imagine any version of Megatron tolerating, or any Vehicon using in the first place.

And he certainly didn’t act like someone who thought he’d be easily disposed of. There was a certain snap to his replies, a willingness to provoke, that was most unlike any Vehicon Ratchet had ever encountered—or any Autotrooper, for that matter.

Then there was the comment about his word carrying weight with Megatron.

Crankshaft was hiding something. 

It was undeniable when Ratchet returned from bridging Arcee and Bulkhead back from a mission and found Crankshaft muttering to himself in Vosian. He didn’t say a thing, let the sudden silence speak for him, and went back to work. 

Crankshaft was unusually quiet after that.

“I think I’ve found something,” started Ratchet, then was cut off by the door sliding open. 

An unfamiliar voice said, “Lord Prime said I had to get this welded.”

Ratchet turned.

And stared.

Because that was Bumblebee in the doorway, doorwings down, optics huge, and a gash across a shoulder leaking sluggishly.

“Uh. Doc?”

“Yes, yes, getting to it,” said Ratchet, and then for good measure, “It’s not as if I don’t have more important things to do.”

Bumblebee all but cowered, and Ratchet tried not to wince guiltily. “Sit down,” he said, instead.

He ignored Bumblebee’s surprise when he deactivated the pain sensors around the area, and finished the job in silence, trying not to let his own discomfiture show. Certainly, the medical records showed that this Bumblebee had never sustained the injury his counterpart had, but it was another matter entirely to hear his voice.

Ratchet’s counterpart had never been presented with the opportunity to fail Bumblebee as Ratchet had.

“There,” he said, stepping away after reactivating the sensors. “Don’t do it again. My time is valuable.”

“Uh. Thanks, Doc,” said Bumblebee, raising a hand to the weld. Ratchet slapped it away. 

“And don’t do that. It’ll take longer to heal if you pick at it.”

Bumblebee eyed him, a most un-Bumblebee-like suspicion in his field. “Since when do you care?”

“Since your repairs took time away from my _valuable research_ ,” snapped Ratchet.

“Uh, yeah right.” Bumblebee stood up. “Look, Doc, wasn’t going to tell you about this one, but Prime thinks you’re hiding something. He’s pretty steamed about it. So word of advice, come clean with him. You remember what happened last time.”

“I’ll keep that in mind,” said Ratchet, turning back to the lab bench. 

“It’s your skidplate,” said Bumblebee. “Hey, is this the same ‘Con from before? You put his leg back on.”

“Yes, I did. Now go away.”

“I guess you didn’t appreciate me taking all that trouble to remove it, then. See you around, Doc!” 

Ratchet turned to look at him, but the door had already slid shut behind him.


	6. Chapter 6

The little medic and the false Prime were not only intimate, they were sparkbonded. 

There was even a note of it in the medical records, as if it were unremarkable, not an act of the greatest sacrilege. There was a _note_ of it, as if medical matters were more important, as if they weren’t ashamed! A mere doctor, a medic who was only a medic, no warrior at all, _daring_ to lay hands on the very spark of a Prime! A Prime so defiled as to welcome that!

It was enough to make one purge. 

Ratchet turned his back on the screen in disgust.

At least it wasn’t long now. His Prime, the true Prime, would arrive and these pretenders would reap the rewards of their folly.  They would scream. They would beg the forgiveness of the god they had so defied, and they would not receive it. Such hypocrisy, such wanton, shameless lust, deserved no other reward. 

The Lord Prime would be so pleased at what Ratchet would deliver to him. So pleased, so proud. He was the Lord Prime’s greatest follower, and all the universe would know it.

“Are you well, old friend?”

Ratchet favored the false Prime with a smile. The concern on the traitor’s face amused him deeply. “Yes, perfectly. This project has proven somewhat difficult, but I am quite close to a breakthrough.”

_Tonight_ , he thought, pretending to listen to the false Prime’s words. _No more waiting. No more staying my hand. Tonight._

 

* * *

 

“I think I’ve found it,” said Ratchet, staring up at the screen. “Here—”

“You’re going to have to be somewhat more descriptive than _that_ ,” said Crankshaft. “ _I_ can’t see the screen from here.”

“It’s something with an autosend date,” said Ratchet, “and given the amount of trouble it gave me to even _find_ , it must be fairly important.”

“Then stop telling me how important it is and fragging open it,” said Crankshaft.

Ratchet opened it. And stared. 

“Oh no,” he said. 

“Ratchet—”

“Crankshaft, were you serious about Megatron providing assistance?”

“ _Ratchet!”_

“Because if this is accurate, my counterpart planned this, and the time he meant to send this is only a few hours—”

Ratchet became aware of a mass at his back, heavy ventilations stirring the air around him. He looked up.

And into Optimus’s optics.

“—away,” he finished.


	7. Chapter 7

It was so, so easy.

Ratchet smirked at his prize, the expression of helpless confusion in the pretty blue optics, the way they widened, minute components adjusting. It was almost a pity that the mouth clamp got in the way. He would have loved to see this other Prime without it, open and vulnerable. 

The stasis cuffs were on their highest setting, so there was little risk of this pretty banging around and attracting attention. With his arms secured and legs hobbled, all he could do was stare. 

Ratchet let him, leaning back against the wall. 

“Poor, foolish Optimus,” he said. “So you and this little medic have an affair. How scandalous. How fortunate for me. It was so easy to get you to let your guard down. A blow to the helm, and you’re mine. Or, rather, the Lord Prime’s, when he gets here.”

Optic ridges rose, questioning. 

“Why? Other than that you sicken me with your hypocritical moralizing and debauchery and humans, your mockery of everything a Prime should be? Because I serve my Prime. I serve him well. And here I present him with a whole new world to conquer and his only opposition a prize at his feet.”

He paced around Optimus, watching the false Prime’s optics try to follow him. “It’s almost easy to hate your little medic, you know,” he said. “My Prime is above such things as love, but you give it so easily. All your little shareware has to do is smile and you’re falling over your own brightly-painted pedes to please him.” He chuckled. “We’ll see how he’s fared with my Prime. He doesn’t tolerate insolence nearly as well as you do.”

A twitch and a murmur. Ratchet was impressed; it must have taken all of the false Prime’s strength to do even that much through the cuffs. 

“Oh, don’t worry. You’ll know how he is very soon. The rendezvous time is only a few hours away.”


	8. Chapter 8

Ratchet lunged for the panel, slamming a hand down on the key that cleared the screen before the other Optimus could read its contents. A heavy hand descended on Ratchet’s shoulder, and when he tried to move away a second one caught him and held him in place. The faint brush of Optimus’s field was filled with cold rage. 

Optimus turned him around, meeting and holding his gaze with crimson optics that blazed. “You have been lying to me, Ratchet,” he said, and Ratchet shuddered. 

A hand caught him under the chin. “Do not dissemble further. What have you done?”

“I—”

Optimus’s field flared out around him, infinitely more painful than the brief stabs he’d inflicted before. Ratchet cried out, dimly feeling himself pinned against the lab bench, a hand around his throat. 

The pain faded, leaving him panting and shaking. “You can tell me anything you need to, Ratchet, you know that,” said Optimus’s voice, and Ratchet whined low in his vocalizer. “Why would you lie to me?”

Ratchet clutched at the lab bench and stared up at Optimus, fighting against the desire to purge his tanks. He couldn’t tell when Optimus had released him, but it didn’t matter; he was trapped between the bench and Optimus with nowhere to go. He cowered when Optimus caught him under an arm and hauled him upright. “Show me what you were reading,” he said. “You were quick enough to hide it.”

Ratchet shook his helm. This Optimus couldn’t be allowed that information.

“Ratchet,” the voice was soothing, gentle, but the hand under his arm clenched hard, damaging lines and cables, “I’ll find out eventually, even if I have to put you in the place of your pet first. Show me.”

“No!” It took effort to say it, and the look Optimus fixed on him made his tanks lurch again. But Optimus merely leaned forward and touched the key Ratchet had moments ago.

There was a long silence as he read, and Ratchet shuttered his optics and stayed still, seeing the words again in his processor.

It was all planned. The groundbridge. The exchange of sparks. Everything. Crankshaft was present because the other Ratchet had thought the experiment unsuccessful, yet not had enough time to run a spark spectra analysis to confirm it. The other Ratchet planned to do something, something involving taking his place and then meeting this Optimus with a prize. Preset time, preset coordinates.

And, at the end, a note that his body did not contain Ratchet but his counterpart, who would try to sabotage the plan if given the chance.

“I see,” said Optimus. “This certainly explains a great deal.” He looked down at Ratchet, considering. “Tell me, do you have a Prime of your own?”

Ratchet took refuge in offense. “He’s far more of a Prime than you are.”

Another long, level look. “I see. And this ‘prize’ my medic speaks of?”

“If I knew, I wouldn’t tell you.”

“There is no need for that,” said Optimus. “We have other materials at our disposal, and it stands to reason that, while Ratchet may be perfectly confident in his ability to succeed in his mission, it would be wise to gain whatever information is possible about this alternate universe.”

Ratchet’s optics went to Crankshaft. 

“Do not be so concerned, Doctor,” said Optimus, following his gaze. “There is no need to be uncivilized, not when we have the cortical psychic patch at our disposal.”


	9. Chapter 9

“No!” Ratchet tried to retreat, but there was nowhere to go. Optimus caught him by the arms and he flailed helplessly as he was lifted off his pedes. He kicked, hard, at the junction between thigh and pelvis, always sensitive, and Optimus made a sound of surprise and dropped him. Ratchet scrambled upright, scrabbling at the terminal for something, anything of use. 

Crankshaft.

He slammed a palm down on the release for the restraints, or tried to; his desperately seeking fingers brushed the edge but Optimus caught him from behind, a huge hand wrapping around his upper chest, rough fingers flexing the glass of his window. He yelped in pain, tried to struggle free, and Optimus’s hand clenched hard. 

The sound of breaking glass was drowned out by his cry, and he went limp in Optimus’s grip, not wanting to move and make the pain worse.

“Remain still,” said Optimus. “Resist further, and I will be forced to break the other one.”

“Frag you,” Ratchet gasped, trying to find the will to struggle. “I’m not helping you.”

A second hand wrapped around his other side, a gentle pressure. “You forget,” said Optimus, “I have known this frame of Ratchet’s a long, long time, and have many times had to put him in his place. Do not push me, Doctor. Comply and you will not be further harmed.”

“Unlike you, my Prime is worth it.” Ratchet dug his fingers into the distal joint of Optimus’s index finger and pressed, _hard._ The pressure on his damaged door lightened. “I won’t let you—or anyone else—injure him, and I _certainly_ will not _comply_.”

Optimus slammed him into the floor. The glass of his other door shattered. 

“Touching,” said Optimus. “But useless. Clearly, I will need to take further measures to subdue you.”

He dug his fingers under the edge of one of Ratchet’s doors and wrenched. Ratchet screamed. 

Optimus lifted him as if his heavy medic’s frame weighed nothing, and carried him across the room to the examining berth. He pushed him down onto it and kept him there with a hand on his chest as he activated the restraints. Ratchet was too dazed to resist, his vision fritzing from the last blow against the floor, his entire torso a mass of pain. 

“No,” he whispered, as a momentary flicker of clarity showed him Optimus lifting the cable for the cortical psychic patch in delicate fingers. “No, please—”

Optimus bent over him. “Enough,” he said into Ratchet’s audial. “Your loyalty is admirable, but will do you no good.”

Ratchet struggled weakly, but Optimus was already reaching around to the back of the table to connect the cable. He flinched again as Optimus’s field brushed over him, full of vicious satisfaction. 

There was a clang. The blur of Optimus’s optics grew brighter, went dark, and Ratchet yelped as Optimus’s weight landed on him. 

The restraints vanished.

“Time to go,” said Crankshaft’s voice, and a hand clasped his wrist, pulling him from under Optimus. “He won’t be offline long.”


	10. Chapter 10

Ratchet staggered, caught himself with a hand on the lab bench. 

“Come on!” said Crankshaft. “Or do you want to be around when he wakes up? I don’t know what sort of soft-sparked Prime you’ve got, but this one won’t take kindly to being smacked upside the helm.”

Ratchet ducked his helm in a nod and looped Crankshaft’s arm over his shoulders—the Vehicon was wavering where he stood and there was no way he was letting someone missing a quarter of his vital systems go wandering around without support. 

“I won’t have time to adjust the groundbridge,” he said, pulling the portable drive from the workstation. “Not before Optimus and the other Autobots stop us.”

“Not necessary,” said Crankshaft. “We just need to get back to the Nemesis. If, that is, you can get my communications suite back online.”

Ratchet nodded, and they staggered toward the door.

Behind them, there was a groan. 

Ratchet didn’t stop to look, just ducked and scooped Crankshaft up in an emergency carry, and took off at a shambling run. The injured servo in his door protested with every step; it was certainly sprained at the very least.

They reached the groundbridge before any of the Autobots made it into the main room. Ratchet set coordinates at random, leaning forward to keep Crankshaft balanced over his shoulders, then activated the bridge as Optimus came pounding around the corner, the other Autobots close behind. Ratchet turned and fled into the groundbridge. Behind him, he heard Optimus’s voice rise in a command; energy scorched the backs of his legs as a blast from Optimus’s ion cannon missed by a frighteningly small margin.

He tumbled out into hot, dry heat, a confusion of tumbled and broken rocks, and Crankshaft said urgently into his audial, “Hide, they’re right behind us!”

Ratchet did as he was told, ducking into the cover of a particularly large outcropping, already reaching for one of Crankshaft’s medical ports to restore his communications. The sound of engines grew louder, distracting him. Crankshaft couldn’t defend himself, and while Ratchet was occupied restoring his communications they were helpless.

He fumbled desperately for the reactivation codes, found them at last and initiated them. 

He withdrew. Crankshaft raised a hand to his audial. “Crankshaft to Lord Megatron—”

“Found them!” 

They looked up. Wheeljack grinned down at them from the top of the outcropping, blasters leveled. “Hey, Doc. Thought you’d seen the last of me?”

Ratchet brought out his own weapons.

“Play nice and I won’t scrap your pet,” said Wheeljack.

Claws wrapped around Ratchet’s arm, and Crankshaft yanked him to his feet, took off at a shambling, irregular run. “Trade insults later,” he snapped, and flinched aside as Wheeljack’s shot went wide. 

Ratchet risked a glance over his shoulder, only to see the Autobots swarming around the outcropping, Optimus and Wheeljack in the lead. 

A groundbridge flashed to life in front of them. Something hit the ground beside Ratchet and Crankshaft yelped and stumbled. He lifted the Vehicon again and staggered into the safety of the bridge. 

Darkness at the other end, a cacophony of voices, and Ratchet stumbled and fell with an undignified yelp as his injured door was jostled. The groundbridge snapped shut. He pushed himself upright.

He was surrounded by Vehicons, blue visors gleaming, weapons leveled and whining with charge. He looked down at Crankshaft. The Vehicon was unconscious, his leg gone below the knee. Energon spattered both of them. 

He reached to work on the welds, but the Decepticons took that as a threat; Ratchet raised his hands before he got shot and said, “I’m a medic! You don’t want him to bleed out, do you?”

Uncertainty. He took that as as much of an approval as he was likely to get and went to work sealing the ruptured lines—thankfully, a short task.

He was almost done when pedesteps shook the decking and an all-too-familiar voice said, “Dreadwing, take the Autobot into custody. Knockout, attend to Crankshaft.”

Ratchet looked up and into blue optics. He froze, armor fanning out defensively.

He looked like Megatronus, he thought, shocked. Red where there should have been purple. Optic ridges rounded. Dentae blunt. Scars crossed his face, but they were new, still healing. And the intent regard that this Megatron bent on him was nothing like the fierce cruelty the other Megatron radiated. Oh, he was angry—Ratchet could feel it in the wash of his field from here—but there was none of the pleasure he’d felt from his Megatron, none of the predator playing with its prey. 

“Move.” Knockout—at least, that was who Ratchet assumed he was, even if he was bright blue—pushed him aside and knelt next to Crankshaft. “Huh. Better work than _your_ usual.”

Ratchet kept a protest back as someone seized him by the shoulder and pulled him away from Knockout. Stasis cuffs snapped over his wrists. He glared up at Dreadwing, who frowned back.

“What brings you here, Doctor?” Megatron’s voice was still a threatening rumble, and Ratchet reset his vocalizer reflexively, looking up at him. 

“I need your help,” he said, first thing to come to processor. “There’s been an accident—”

Megatron stepped forward to examine him, optics stopping on his injured door. “And I am willing to bet that the accident’s name was Optimus Prime,” he said after a moment. “Speak quickly, Ratchet. After what you have done to…” and yes, it was there, it wasn’t Ratchet’s imagination, there was a distinct pause, “Crankshaft, you must know that I am not particularly disposed to be... _understanding_.”

Ratchet looked to Crankshaft. He was still unconscious. “We don’t have time for this,” he snapped. “I’m not Ratchet. The Autobot medic has found a way to cross dimensions using the groundbridge, and he is executing a plan that I have good reason to believe will begin an attack on my own universe. We must move quickly, before he and Optimus succeed.”

There was dead silence. Megatron’s optic ridges went up. 

“Yet you look exactly like him,” he said after a moment.

If his previous statement had been so badly received, Ratchet dreaded to think what they’d think of this one. “He has found a way to transfer sparks between frames,” he said. 

Megatron and Knockout were sharing a significant look now. “It would explain…” started Knockout, optics going to Crankshaft’s unconscious frame. Megatron cut him short with a gesture. 

“You say that you are not Ratchet?”

“Not this one, no,” said Ratchet, the words coming slowly with all the suspicious regard on him. This was seeming like a worse and worse idea with every second. “His counterpart. An alternate version of him from the dimension he is attacking.” He reached into his subspace for the portable drive, wincing as the whine of weapons intensified. “Here is all the pertinent information.”

Megatron bent to take it from him. 

“Please hurry. He plans to execute his plan in only a handful of hours.”

“Soundwave, examine this,” said Megatron. “In the meantime, Dreadwing, confine our guest in the brig. We will see whether this...tale...agrees with Crankshaft’s recollection of events.”

“No!” Ratchet struggled against Dreadwing’s grip. “We don’t have _time_ for this, Megatron! The mech who did that—” he jerked his chin at Crankshaft, “is loose in my universe, using my frame and my voice and _nobody there knows!_ You know how dangerous he is! They don’t, they think he’s me— _for Primus’s sake he’s in close contact with the humans!_ ”

Megatron stilled in the act of turning away. He looked back over his shoulder, a slow, deliberate gesture, and the light in his optics made Ratchet’s spark still with fear.

“Since when,” Megatron said, very quietly, “have you cared about humans?”

Ratchet just stared at him. 

“Confine him,” said Megatron, and stalked from the room.

“No!” Ratchet lunged forward again, but Dreadwing restrained him easily. “Listen to me! _We don’t have time for this!_ ”

Megatron made no sign of hearing him. 

“Just let me use your groundbridge! Please! I’ll be gone, you won’t see me again—just let me go!” They were going to stop him, they were going to keep him here and all the time Optimus would be in that monster’s hands— “Megatron, please! You have to let me stop him!”

This time Megatron did stop. “I am not risking my people’s lives on the panicked assurances of an Autobot,” he said. “Especially yours, Doctor.”

_“My bonded is at that sick fragger’s mercy, you moronic progeny of a trash compactor!”_

But Megatron made no sign of hearing him. 


	11. Chapter 11

Ratchet watched the hours tick by on his chronometer and paced. His door ached, but there wasn’t anything to be done for that. The transformation protocols in his arms were disabled. And they’d used stasis cuffs on him, warframe-grade. 

If the situation was different, he would have been amused. 

Instead he paced. And swore, and paced more when it became evident no one was listening. 

The rendezvous time was getting nearer. 

His tanks churned. What, exactly, was the ‘prize’ his counterpart had referred to? One of the Iacon Artifacts they’d captured? The base? Primus forbid, the Matrix itself?

That thought was enough to stop Ratchet where he was. He’d had too many nightmares of Optimus gray and offline. Thinking about it seemed to invite the possibility. 

Optimus was alive, at least—he’d know otherwise. It was something at least to hold on to. 

The door opened. Ratchet turned to level a glare at it. “So, have you come to your senses?”

Megatron raised a sardonic optic ridge. “And what would you mean by that, Doctor?” He stepped aside to allow Crankshaft entrance. The Vehicon was limping, but Ratchet noted with relief the competent welding job on the leg, and the increased strength of his field. Crankshaft nodded at him.

Megatron reset his vocalizer and Ratchet realized he expected an answer.

“Soundwave must have examined the data on the portable drive by now.”

“He has,” said Megatron. “However, the fact remains that you might have planted it as part of an elaborate trap. Optimus Prime has resorted to such tactics in the past.”

“It’s not a trap,” snapped Ratchet. 

“So you have assured us,” said Megatron, “with remarkable desperation. Tell me, Doctor, if it is such a very important motivation, to whom are you bonded?”

Ratchet sputtered. “I don’t see how that is _any_ of your business,” he snapped, once he’d regained enough composure to speak. “What is pertinent is that my counterpart—this bot whom you all _fear_ , is impersonating me and has the opportunity to cause untold damage as a result!”

“It’s a simple enough question,” said Megatron. He moved closer. Ratchet took a step back, looked for help from Crankshaft.

Crankshaft leaned back against the wall and folded his arms, shoulders lifting. 

“It hardly matters!”

Megatron looked down at him, not smiling. “Think of it as a gesture of goodwill, Doctor.”

“The readings that Knockout got off you do seem to indicate you’re bonded,” said Crankshaft. “So you’re not lying about that. The question is, to whom?”

“I…” Ratchet looked from one to the other. “It’s private.”

Megatron straightened up with a resigned huff of vents. “Very well.” He turned toward the door.

Ratchet took a step after him. “Why does this _matter_?”

Megatron ignored him. 

Ratchet’s processor whirled with fear and desperation. It presented him again with the image of Optimus, gray and offline, Optimus bending to touch helms with him, absolute trust in his field and optics—

“It’s Optimus,” he blurted, before he could think better of it. 

Both Megatron and Crankshaft froze where they were, then looked at each other.

“You were right,” said Megatron, with something like restrained surprise in his voice.

“I’m always right,” said Crankshaft, and straightened up. “Even Ratchet couldn’t keep such good control of his field and say _that_. Not of Optimus Prime. No Autobot would.”

“So this was a _test_?” Ratchet’s voice rose sharply. 

“Yes,” said Megatron. “Recall that the Optimus Prime you have had close encounters with here, who attacked you—” he gestured at Ratchet’s door, “—a mech he hardly knew, with little provocation, is the same mech who has vowed to offline and eliminate every last trace of ‘Decepticon vermin’ from the universe.” His mouth twisted at the words. “I don’t have the luxury of easy trust, Doctor.”

“And yet  the idea of me being sparkbonded to this Optimus is absurd enough that you’re now willing to take me at my word.”

“You’ve seen how his Autobots behave around him,” said Crankshaft. “He is hardly a kind or approachable leader, and he and Ratchet punish ‘lustful’ behavior with _great_ enthusiasm. Ratchet would never be able to claim that he was Prime’s bonded. No Autobot would—even they can’t lie that well.”

“And even if one—Wheeljack, for instance—could,” said Megatron, “they could hardly counterfeit the emotion or the intensity of the emotion that just went through your field. No, Doctor, this is indeed evidence enough. It corroborates what Starscream has already told me; I simply wished to see you react for myself.”

“Starscream?!”

Crankshaft would have smirked if he had a mouth. It was written all over his field. “Not my original frame. I told you as much.”

Ratchet bridled. “Certainly, I _suspected_ something, but— _Starscream?!_ ”

“Enough,” said Megatron. “We have more urgent things to attend to than Starscream’s current predicament. If you will accompany us, Doctor?”


	12. Chapter 12

Ratchet found his Prime waiting for him at the prearranged coordinates, far earlier than their arranged meeting.

Up close, the differences between him and the false Prime were stunning. The false Prime looked still more foolish, his gaudy paint scratched and scuffed, a pitiful thing next to the Lord Prime’s somber polish. The wide blue optics looked weak and dim, and Ratchet felt entirely appropriate pride swell in his spark as his Prime leaned down to examine his heretic counterpart. Let the traitor see what a true Prime looked like, how a true Prime comported himself.

“A prize indeed,” said the Lord Prime, and touched precise fingers to the planes of the mouth clamp. He paused, considering, and then with a sharp gesture freed it.

His alternate looked up at him with mouth pressed tight. He tried to bring out the battlemask, but the Lord Prime forestalled the cowardly gesture with a finger over the traitor Prime’s mouth. 

“There is a Matrix within you,” said the Lord Prime. “I can feel it even from here. Yet you ignore its dictates so very well.”

The traitor Prime’s optics lowered.

“I learned much of you from your little medic,” the Lord Prime said, and that brought the traitor’s optics up. “He presumes to address you by name. He presumes—”

“Lord Prime,” said Ratchet, smirking, “he presumes far more than that. He and this Prime are conjunx endura.”

The Lord Prime’s attention snapped back to the traitor. 

“Is this true?” he demanded, and to his pleasure and surprise Ratchet heard true rage in his voice. The heretic Prime turned away from him, optics shuttered. 

The Lord Prime struck him with a sound of metal on metal. “You, a Prime, and a _medic_? You presume to dirty your spark, dirty the Matrix itself, with _that_?”

“Dirtying my spark?” said the false Prime slowly, and Ratchet knew his Prime well enough to detect the far quieter echo of anger in the even voice. “He is a healer.  You propose that intimacy with him—or with any other Cybertronian, any of Primus’s creations—diminishes me?”

“Heresy,” said Ratchet. The Lord Prime forestalled him with a raised hand.

“You ask me what is wrong with such a coupling,” said the Lord Prime. “You expose the Matrix to a lowly creature, and so corrupt everything that you are.”

“I too, am Cybertronian,” said the false Prime. “I am the same as they are, and it would be wrong to place myself above them. My role is to serve, not to rule.”

Ratchet snarled. “You forget your place, heretic. Do not question the Lord Prime; you deserve offlining for your impertinence.”

“Enough,” said the Lord Prime. “We have more useful things to do with our prisoner than simple offlining.”

He hauled his counterpart upright. “We are still lacking in information about this universe and its Autobots,” he went on. “The little medic escaped before I could perform a cortical psychic patch; he is now likely lost to us, as the Decepticons are unlikely to have allowed him to live once he arrived aboard their ship. He was, after all, wearing your frame.”

The traitor Prime’s optics went wide. “No…”

“Then we should act quickly, Lord Prime,” said Ratchet. “Have you a remote to the groundbridge?”

“I do,” said the Lord Prime, and activated it. The groundbridge flared to life. 

Ratchet smiled. He had served his Prime well.


	13. Chapter 13

They were too late.

It was all Ratchet could do not to collapse to his knees as the other groundbridge winked out of existence, taking Optimus with it. He’d only caught a glimpse, blessedly familiar red plating, stasis cuffs—but his own groundbridge had opened too far away to do anything. 

A heavy hand descended on his shoulder. He flinched. 

Megatron removed the hand, looking uncharacteristically contrite. “I’m sorry, Doctor,” he said. “There is little we can do for your bonded now. By the time we found him, he might already be offline.”

“I refuse to believe that,” snapped Ratchet. 

“Autobot protocol with prisoners doesn’t leave much room for optimism,” said Starscream. “A cortical psychic patch to extract information, then execution. He has maybe two hours at most—and that’s if he’s uncommonly good at resisting the patch.”

Ratchet didn’t know. He and Ironhide had spent hours upon hours worrying about exactly that; while there was limited training intelligence mecha underwent that could at least _slow_ a mental attacker, it carried with it considerable risks. The official medical consensus when it came to the cortical psychic patch problem as applied to the Prime was ‘don’t let it happen in the first place’.

That consensus had gone right out the window with their arrival on Earth, but the reasons behind it remained; with all the risks of processor damage a cortical psychic patch represented, they could not afford to have Optimus undergo one, not even the limited version used in training intelligence mecha.

Ratchet’s hands curled into fists. He was _not_ leaving Optimus to that.

“Then we’d better hurry,” he said, turning back to the bridge. 

“What?” It was Starscream who caught him by the arm this time. “You’re glitched. We don’t even know where the Autobot base is!”

“You do not,” said Ratchet. “I do.”


	14. Chapter 14

He’d startled Starscream into silence. 

Megatron’s optic ridges had risen considerably, but he already wore an evaluating expression, no doubt working out how he could turn this pronouncement to his advantage. 

Which was worryingly easy, but Ratchet was trying not to think about that. He reset his vocalizer. “Well? What are you waiting for?”

“You are correct,” said Megatron. “We do not. Come along, Starscream.”

“So we’re raiding the Autobot base?” shrilled Starscream, a pitch that should not have been possible with the Vehicon’s vocalizer. “Just like that? Just because Ratchet’s ‘good’ counterpart claims he knows where it is?”

Megatron was already well ahead of both of them, calling for a groundbridge. He paused at that and looked over his shoulder. “This war has gone on long enough, Starscream. If we are offered such an opportunity to end it, it would be folly to refuse. We owe the dead that much at least.”

Starscream looked down. After a moment he nodded, very slightly.

There was something to both their fields that Ratchet couldn’t place, something almost like guilt. 

The bridge opened in front of them, and they stepped through. 

And almost directly into Knockout, who cocked his helm and said, “Megatron, Agent Fowler wanted a word with you.” 

He extended a hand, and Ratchet stared, because that _was_ Agent Fowler, Agent Fowler exactly, indistinguishable from the Fowler in his own universe except for the hatred on his face as he looked back at Ratchet. 

“Megatron,” he said, voice rising at the end of the word in the way that it did when he was truly angry, “ _what_ is he doing here?”

“Assisting—”

“You know what he did to the kids!” Fowler jabbed a finger at Ratchet. “So you’re going to _tell me_ what exactly _is going on here!_ ”

“The kids?” said Ratchet, looking to Starscream for an explanation. A horrible suspicion rose in his processor. “Oh no…”

“What, don’t tell me you have amnesia too!” Fowler turned his attention to Ratchet. “You know damn well what you did.”

“Agent Fowler,” said Megatron, raising a hand. Somehow it wasn’t threatening. “Allow us to explain. This is not the Ratchet we are familiar with, but rather someone who was as much a victim of his machinations as any of us.”

“He sure _looks_ like Ratchet.”

“That’s because everyone’s least favorite medical professional has found a way to hop frames,” said Starscream. “I was the test subject. The doctor here is the final project.”

“Fine. Then who is he?” Fowler folded his arms.

There was a pause. 

“I don’t like that silence.”

Megatron let out a heavy ventilation. “The good agent did believe us about Unicron,” he said to Starscream, as if he were trying to convince him of it.   
“Okay, what’s more unbelievable than _Unicron?_ ”

“The Autobots have found a way to use the groundbridge to breach the boundaries between dimensions,” said Ratchet, losing all patience. “As far as we have been able to determine, they have hostile intentions toward my home dimension, and the first step in that process has been stealing my frame to infiltrate our base and abduct _my_ Prime. Now, if you’ll _excuse_ us, we have a rescue to plan.”

“That doesn’t answer my question,” said Agent Fowler. “Who are you?”

Ratchet hesitated, glanced at Megatron, who inclined his head in a nod. 

“Ratchet,” he said, and saw Agent Fowler’s eyes narrow. “From a universe in which the Autobots _defend_ Earth.”

“Let me get this straight. You’re saying we should trust you because ‘this universe’s’ Ratchet has gone and pulled some Star Trek stuff with the groundbridge? And that you’re Ratchet but the good version?”

“A remarkably astute observation,” said Ratchet. “Are we _done_ now?”

“Oh, _we_ are,” said Agent Fowler, and looked at Megatron. “However, you and I are going to have a _conversation_ about this which you will _not_ enjoy.”

Megatron seemed grimly amused by this. “Make an appointment, Agent Fowler. In the meantime, we have a war to end.”

“A war to end?” Megatron started walking, and Agent Fowler balanced in Knockout’s open hand with the ease of long practice. “Megatron, what happened?”

“The medic did,” said Megatron. “He knows the location of the Autobot base.”

Agent Fowler turned his attention to Ratchet. “And what’s your angle here?”

Ratchet hesitated, but frag it, Megatron already knew. The scraplet was loose. He let out a heavy ventilation. “They have my bonded,” he said, reluctance in every syllable. 

“Who is…?” 

Megatron looked like he wanted to say something, but restrained himself. 

Ratchet glared straight ahead. _There’s no choice_ , he reminded himself. “Optimus.”

Fowler sputtered. Then, “Okay. Okay, I see why you believed him.”

“Glad I could convince you,” muttered Ratchet. “Now, if you are done putting me on display for the amusement of all and sundry, could we proceed? There’s only a life at stake, after all.”

 


	15. Chapter 15

The next hour was a haze of activity, and yielded some unexpected results. 

“Soundwave made the schematics available to me as soon as he judged them genuine,” Knockout explained, putting a wicked-looking device on the lab bench. Ratchet glanced over at Starscream and the real Crankshaft, Starscream leaning with his customary grace in his borrowed frame against a wall, while Crankshaft stood uncomfortably in the center of the room, wings down. 

Knockout looked at the two again. “The sooner we can get them back into their frames, the better,” he confided to Ratchet. “Crankshaft was in bad shape when the switch happened; the fact we had to confine him to the brig when we noticed inconsistencies in his behavior hardly helped.”

Ratchet looked at Crankshaft again. While it was Starscream’s frame, he’d never seen it look less like Starscream. “It says much for his presence of mind that he was able to fly to the Nemesis in the first place,” he said.

“If you two are _quite_ done talking about us behind our backs, we do need to be transferred back into our real frames now,” called Starscream. “I _would_ like to be able to _fly_ again, you know.”

Crankshaft laughed nervously. “Very well, sir! I’ve had my fill of it.”

Knockout fiddled with the gun. “You two do understand this may not work, correct?”

“Yes sir,” said Crankshaft.

“You’ve only said that thirty-odd times, Doctor,” said Starscream. “Hurry up with it.”

Knockout pointedly ignored him. “You can adjust the settings here and here,” he said to Ratchet, pointing at the device in his hand, something that resembled nothing so much as a very small handheld blaster. “Set first target by doing _this_ ,” He twisted one dial, and then pointed it at Starscream, “and then initiate by doing _this._ ” He touched the other dial, then pulled the device’s ‘trigger’. 

There was no flash of light, not even the thud of displaced air. Starscream and Crankshaft simply both sat down abruptly, blinking. 

“I have my wheels again!” said Crankshaft happily, while Starscream hauled himself back to his pedes. 

“Spectacular work as always, doctor,” he said, pausing in the door to admire a claw. “Now, if you’d just send Ratchet with me, we can get to work.”

* * *

 

Not much later, Ratchet found himself on the bridge of the _Nemesis_ with the device in hand and Megatron briefing him with an expression of uncharacteristic concern, which looked very odd on him indeed. “We cannot afford to lure the Autobots away from the base in order to facilitate the rescue,” he said. “Ideally, you will be able to retrieve Optimus before the other Autobots have time to attack; however, we will have a unit standing by to provide backup should you need it. The fewer of ours we have in there, the better; it means fewer to extract before we complete the final phase of the attack.”

Ratchet nodded curtly. “Understood.”

“And don’t get cocky,” said Starscream. “We think we’ll be able to set you down right by the infirmary, but that’s no guarantee. I should hope that you’ll have more sense than to try and take on all of the Autobots on your own but in case you’re tempted to try it, _don’t_.”

Ratchet huffed. “Understood. Can I _go_ now?”

“Of course,” said Megatron. “And Doctor?”

“Yes?” said Ratchet, turning his attention away from the Vehicon feeding coordinates into the groundbridge.

“Thank you.”

“Hardly,” said Ratchet. The groundbridge came to life. He looked down at the device in his hands, already with the first frame set; himself. All he needed to do was press the trigger at just the right time to get himself back into his body. “I should be thanking you.”

It was odd indeed to be saying that to Megatron of all people, but it didn’t make it any less sincere.

* * *

 

As promised, they managed to set him down just outside the Autobot infirmary, and first stroke of luck since landing on in this fragging universe, the corridor was deserted. Ratchet let out a deep, grateful ventilation, and pressed himself against the wall, reaching for the keypad to get in the door. 

The door slid aside. He paused again, but there was no outcry, no blaster fire, and he sidled around the corner and ducked behind the cabinet. No sign anyone had heard him. Thank Primus. He straightened up and looked over the top of the cabinet.

His intake dried with horror. 

His counterpart stood over the controls to the cortical psychic patch, watching a monitor intently. 

Optimus lay on one of the berths, heavily restrained, a mouth clamp over his intake, optics black and offline. There were scrapes in his paint around the restraints. That little detail made Ratchet’s lines run cold. Optimus must have been badly frightened, to have fought so hard. He knew the risks of a patch, knew he had no defense against it. So he’d fought physically, only way he could, desperately and futilely. 

“Your resistance is useless,” said Optimus’s counterpart, voice made tinny by the monitor speakers. “It will be less unpleasant if you do not fight me so.”

“I will not willingly surrender intelligence that can be used against my Autobots,” said Optimus. “No matter the outcome, I will resist you to the best of my ability.”

“Most unwise. It will do you little good, and your current defiance is making a convincing argument for the merits of leaving you to Ratchet when I have extracted the necessary information.”

Ratchet raised the device, hands shaking. He steadied it and fired.

He staggered with the surprise, with weight differently distributed, and caught himself on the edge of the controls. He groped for something, and his grasping hand caught a wrench.

_Perfect_.

Blaster fire scorched his shoulder, struck the wall opposite. He turned and hurled the wrench with the accuracy of long practice, heard with satisfaction the muffled yelp and sound of a falling frame. The warframe-grade stasis cuffs they’d doubtless used on Optimus lay on the lab bench; very powerful but Ratchet wasn’t much in a mood to ensure his counterpart’s comfort.

He crossed the room in a handful of steps. His counterpart came back online just in time to yelp as the cuffs activated and shocked him back into stasis. Ratchet dragged him into a corner, locked the infirmary doors, and hoped no one had heard that. 

Now to deal with Optimus. 

He deactivated the restraints on Optimus, activated those on his counterpart, and switched the mouth clamp. The problem now was disconnecting the patch. If he did so immediately, it would trap Optimus’s counterpart in Optimus’s processor, and that he did not wish to inflict on Optimus. The initiating party always needed to be the first to withdraw contact.

On the screen, Optimus fell back a pace and his counterpart pushed past him. “Only this last thing,” he said. “And if you are penitent enough, I will consider sparing you Ratchet’s attentions.”

The comm. Ratchet wasn’t surprised to find a new link in his comm suite, and opened it. _Lord Prime, there’s an emergency. The Decepticons are here._

Ratchet let out a long vent of relief as the patch terminated, and turned his attentions to Optimus’s readings as he onlined. 

There was a roar of rage and a crash as Optimus’s counterpart thrashed against the restraints. His comm suite roared to life. _Ratchet—!_

Ratchet ignored him and moved to help Optimus upright. Optimus groaned, very quietly, and put a hand to his helm. 

“I would tell you to take it slowly, but we _really_ don’t have time,” said Ratchet, as Optimus waved him off and pulled himself upright using the berth. “We need to go. The _Nemesis_ will be here any moment.” 

“I will defer to you, as always, old friend.” Optimus tipped a small smile down at him. 

Ratchet smiled back, stepping away. “This way,” he said and something caught him around the waist. He struggled, and the barrel of an ion blaster jammed hard into his side. 

“I long suspected that Ratchet might betray me,” said the other Prime into his audial. “Just not in this fashion. Surrender, counterpart. Or your beloved little medic will take his place in the Pit.”

 


	16. Chapter 16

“No!” Optimus made an abortive gesture toward him, and froze as the other Prime cycled up the blaster pressed to Ratchet’s side. 

“Remain still,” said the other Prime. “My Autobots will be here shortly.” The infirmary doors shook. 

“Those are reinforced,” said Ratchet with perhaps more satisfaction than he should have. “It’ll take a while.”

“Ah. You locked them. Clever little medic. Your false Prime is lucky to have your loyalty.”

“You’re one to talk. You distrust your medic so much you keep override codes to his medical berths.”

“But do you deserve anything more than that, little medic? I am sure you wonder about it, why your Prime tolerates your intimacy.”

“That’s hardly—” Ratchet restrained himself from saying anything further. 

“You have every reason,” said the Prime, softly. “How could you ever hope to be worthy of him? You’re a medic. Hardly worthy to tend to him, in civilized circumstances, let alone share spark and frame.”

“Your quarrel is with me,” said Optimus, and there was real anger over the bond and in the wisp of his field that brushed over Ratchet’s plating. “Leave Ratchet alone.”

“Ratchet has very much involved himself in this,” said the other Prime. “And it is impolite to interrupt.” He turned his attention back to Ratchet. “You’re always afraid that you won’t be good enough for him, are you not? You must know about what he and Megatron shared.”

Optimus went very still at that. It made Ratchet’s spark hurt, though the other Prime words spoke to all his own insecurities, things he and Optimus had discussed. For all the comfort those discussions had brought, the doubt still lurked in his processor, no less potent for being baseless.

“Ratchet—” Optimus cut himself off as a nudge from the ion cannon made Ratchet wince. 

“You’ve always been right,” said the other Prime. “No matter what he told you, that doubt has been his, too. He has wondered whether he betrays his duties, opening to you, and he has kept it from you because he does not wish to hurt you. He is very altruistic—but you know that, do you not?”

Fierce denial pulsed over the sparkbond. The infirmary doors shuddered. 

“You’re lying,” said Ratchet. “We are sparkbonded. _I would know._ ”

“Your spark bond?” said the other Prime. “Oh, little medic, it is hardly a guarantee of honesty. I know so much more of your beloved than you do. He has so very many secrets. How many mecha have you retracted your plating for, my counterpart?”

“It doesn’t matter,” snapped Ratchet. “I trust Optimus with my spark.”

“Ah, but he has not trusted you. He would, if he thought you were good enough. Well, my counterpart, why indeed have you not told your little medic what you’re hiding under your plating?”

Optimus’s optics widened, mouth thinning. Ratchet forced his field calm. “Optimus, it’s all right. You don’t need to tell me anything you don’t want to. I trust you.”

“Maybe you should tell him that you do not know whether it was his or Megatron’s. Maybe you should tell him that you initiated termination protocols.”

Optimus went very, very still. 

Ratchet slammed his helm back into the other Prime’s midsection and drove a heel against his kneecap. The ion cannon jerked and fired, scorching heat across his abdomen, but Ratchet ignored it and squirmed free, comming Megatron as he did. He brought out his blades, slammed one into the elbow joint of the Prime’s arm. Another hand caught him by the plating behind the neck and dragged him back and away from the other Prime, and Optimus placed himself between them, swords raised.

Ratchet tried to rise. Dark spots danced over his field of view, his HUD filling with red damage glyphs before even the pain hit. He curled over himself, feeling energon flow hot and sticky over his plating. 

The infirmary doors burst in with an explosion of heat and light. Clash of metal above him, Optimus’s voice raised in rage. He couldn’t tell which one.

A groundbridge opened. Ratchet let out a ventilation he hadn’t been aware of holding, and the world swirled away as he was lifted, Optimus’s field pressing around his frame, worried and loving.


	17. Chapter 17

“Up, Ratchet,” said the Lord Prime, and Ratchet staggered to his pedes, frame still buzzing with the aftereffects of the cuffs. “Up. We have no time.”

“Lord Prime…?”

“They’ve escaped. We must evacuate. The _Nemesis_ is overhead.” The Lord Prime caught him under the arm and guided him out of the infirmary. “The others have gone. I have set the groundbridge coordinates for you.”

“But Lord Prime, what will happen to you?”

The Lord Prime paused by the bridge. “I place my spark in Primus’s hands,” he said. “Go, Ratchet.”

“My lord, I swore to defend you with my life—”

“ _Go!_ ” The Lord Prime’s field lashed out over him, vicious as a whip, and he dove into alt mode and into the bridge as ordered.

He stopped to look back, in time to see the Lord Prime raise the Star Saber over the groundbridge controls—

He never brought it down. Thunder and rock and dust and heat exploded through the groundbridge, and Ratchet tumbled end over end out into darkness and snow and filth and silence. 

“No,” he whispered, and his tanks rose within him. This was his fault, the result of his ambition, and now the Lord Prime was— “No! Lord Prime!” It choked off in a sob, and Ratchet slumped down under an alien sky, in alien filth and muck, and mourned his Prime.


	18. Chapter 18

The _Nemesis_ had a chapel. 

Optimus had not expected that.

It was hardly more than a storage room, a number of crates set up at the front of the room with spark-globes hovering over them, a memorial to the dead. They were small, but the care in their upkeep and arrangement spoke greatly of their significance to the crew. Optimus bowed his helm and drew a deep ventilation. 

Ratchet would live.

He felt his failure acutely, even though he hadn’t had a hope of defending Ratchet. He knew it wasn’t his fault. He knew that it was useless to blame himself and yet he did. Perhaps it was because it gave him some illusion of control over the whole thing. 

Perhaps it was because he had seen himself in his counterpart’s spark, seen what he might be capable of if he did _not_ take such responsibility for his actions and for his people. This very room, with the muted glow of spark-globes all about him, was yet another reminder of that. 

He was shaken to the very spark, and he did not know what to do. 

Ratchet would live.

Ratchet would live, but how was Optimus to live with himself, having seen the realization of what he might become if he listened to the dark parts of his spark? He had done that already, when he ordered the deployment of the Spark Extractor. He had done that out of desperation and necessity, but now he wondered if he had not had a darker motive that went unacknowledged. Ratchet had sought to pull him back from that, and he had not listened. 

His counterpart had thought Ratchet not good enough for him. 

He was wrong. It was Optimus Prime who did not deserve Ratchet.

It would have been easy to dismiss his counterpart’s actions as the actions of another, eviler mech, but that would have been stepping down the very same path as that counterpart had taken. Optimus knew in the spark of him that he was capable of great evil and it dismayed him more than he could ever hope to verbalize. The events of that day had demonstrated this clearly, and he shuttered his optics and begged silent pardon from the sparks that the globes symbolized, from the many other sparks unrepresented. 

He should have been at Ratchet’s side. 

Knockout had refused him that, said he needed him out from under-pede as he worked, and so he’d retreated here, only place he could imagine not being in the way. 

There had been Agent Fowler’s response, too. Optimus had at first looked at him with delight and relief, but the human’s suspicion had put a stop to that, and his anger when Optimus had asked after the children silenced Optimus’s next words in his vocalizer.

“So even the good twin of Prime is religious. Wonderful.”

Optimus straighten up and looked at the doorway. Starscream smirked at him, no venom to it. 

“I was in the way elsewhere,” said Optimus at last.

“Ratchet will be fine. He’s unconscious and in recovery from the surgery. He’ll be up and about in a few hours.” Starscream looked around the little room. “Fowler says you asked after the kids.”

“I did.”

Starscream glanced sidelong at him. “How do you know them?”

“In our universe, they are our allies.” Optimus looked away, longing abruptly for the base, to feel the familiar fields, hear the children bickering. “I am not pleased by the dangers they face, but they insist. We are…very fond of them.”

“Ah.” Starscream stepped into the middle of the room. “If you wish to know what happened to them here—”

“Please,” said Optimus, raising his optics to the spark-globes. “I believe I owe Agent Fowler that much at least.”

Starscream took a deep ventilation. “It wasn’t your counterpart. It was Ratchet’s.”  He gestured to two globes set apart from the rest, odd and golden, a wavelength of light much like that of Earth’s sun. “Jack and Miko. Ratchet made some kind of anti-organic weapon and turned it on them. The only possible descriptor for the result was ‘splat’.” 

Optimus glanced at him, dismayed by the dismissive wording, but Starscream’s face was set, and he realized that it was Starscream’s way of dealing with the grief. 

“Raf was out of the center of the effect, but the only reason he’s alive is because Knockout’s done his research and managed to get his fluids to coagulate properly again. Even so…” Starscream looked away, “he has still to wake from the coma. It’s been two months.”

Optimus reached out instinctively to place a gentle hand on Starscream’s shoulder. “I am deeply sorry for your loss,” he said. “It would grieve me greatly if harm came to any of our universe’s humans.”

“They weren’t supposed to be there,” said Starscream quietly. “But they wanted to help. Miko—Miko was taking pictures, as she always does—” He cut himself off, resetting his vocalizer. “Megatron was devastated,” he said with more composure. “He was very fond of Miko. Soundwave keened— _Soundwave_ , of all mecha—over Raf, and goes to sit with him every day when he is off duty. And Jack—stupid sparkling, shouldn’t have tried to stop Miko, he _knew_ it wouldn’t work but he had to be heroic, just like Megatron—!”

Starscream was pressing back into his hand with a surprising force. He likely hadn’t had anyone he could voice this to, not Megatron—if this Megatron were anything like the Megatronus Optimus had known, it would only have served to grieve him more deeply. This Starscream was considerate enough to realize that. Soundwave was devastated enough, and Knockout busy enough—

“You cannot blame yourself for this,” said Optimus. “Terrible things happen, but you cannot take responsibility for all of them. You’ve stopped the Autobots; you have stopped those that killed Jack and Miko, and they shall not harm anyone again. It is all you can do.”

“Odd words to hear from _you_ ,” said Starscream, but he straightened up and tucked his field in, composure restored in moments. He cocked his helm, listening to a comm signal. “But there. Now you know why Agent Fowler reacted the way he did. Come along, Prime; Knockout says Ratchet’s ready to come online.”


	19. Chapter 19

The world came back slowly, damage alerts winking blue and fading against the darkness of his shuttered optics. 

“Old friend?” Optimus, strangely tentative, his field spread out and surrounding Ratchet, love and worry. A big hand took his, pressed it. “Old friend, I am here. You are safe now.”

His optics opened, onlined, the world sharpening, and there was Optimus. Alive, unharmed, concerned and strangely grieved. Ratchet managed a smile, and that grief lifted, but not by much.

“Optimus,” he said. “Thank the Allspark.”

“No,” said Optimus, with a gentle smile. “Thank you, Ratchet. You have done so much.” He looked down. “And, old friend, I owe you a sincere apology.”

“For what?” said Ratchet, pushing himself upright. “Your counterpart’s actions are not yours, Optimus. You cannot take responsibility for them.”

“But I must take responsibility for my own.” Optimus drew a deep ventilation, still not looking at him. “I have lied to you by omission.”

Ratchet’s tanks lurched, the other Prime’s words coming back to him. _That doubt has been his, too_.

“When I returned from the _Nemesis_ ,” said Optimus, as if the words hurt him, “I think I was carrying a newspark. I do not know; it was too early in the cycle to be certain. As my counterpart said, I do not know if it was your spark or Megatron’s that might have kindled me. I do not know if I interfaced with Megatron or not. However, at the the time, I was nearly certain I had. It was—” and Optimus bowed his helm, the ghost of old rancid panic flickering through field and bond alike. Revulsion, too. Self-loathing. All tightly contained, and all the more acute for the strict repression. “I could not bear it. Our energon supplies would not have supported a carrier in any case, even if I could have borne it.”

“Optimus—”

Optimus raised a hand. “It was my burden,” he said. “I had put you through so much, old friend. How could I ask that of you as well? I could not hurt you in such a way. So I activated the termination protocols, and did not speak of it. I did not realize that it might be a gesture of distrust.”

Ratchet thought back to the days after Optimus’s return, how he had moved slowly and painfully and kept to himself. Ratchet had put it down to the effects of the Matrix.

Termination protocols were to be used in just the situation that Optimus had found himself in, and they made the mech in question royally ill in the process. Optimus had hidden all that, because he had not wished to burden Ratchet.

“I am sincerely sorry,” said Optimus. “I hope that you can forgive my dishonesty.”

Ratchet stared at him. 

“You big, stupid glitch!” he said at last. “You’re apologizing—Optimus, I may have been hurt that you didn’t tell me, but that was _your_ choice to make, never mine! It was your frame and you’d just crawled out of Pit and—Optimus, it was _your frame_! I do wish you had told me because you shouldn’t have had to bear it alone but it was your choice, your frame and I have no right to be angry on my own behalf. On yours, however—when are you going to get it through that thick processor of yours that concealing and repressing anything that has to do with your own wellbeing is _unhealthy_?”

Optimus’s shoulders slumped. 

Frag, he’d said it all wrong, hadn’t he. 

“Optimus,” he said, gently, “I do not take it as a gesture of distrust. You had every right to keep it to yourself if that is what you wanted to do. What I object to is the pain that it caused you. You must pay more attention to your own wellbeing, physical and mental.”

Finally, Optimus’s optics rose to meet his. “Thank you, old friend,” he said. “You are far more than I deserve.”

Ratchet huffed. “Than you deserve?” he said. “Don’t be absurd.”

Optimus forced a smile. His field did not become any happier. 

“Come here,” said Ratchet, reaching for him, and Optimus leaned into his arms gratefully, pressing his helm into the crook of Ratchet’s neck and curling around him as if he wanted to protect him from the universe itself. Ratchet ignored the sting of new welds and pressed up against him, wrapping both arms over Optimus’s back, feeling the heat of overstressed systems, the guilt/love/relief of Optimus’s field around him.

“Stop that,” he said after a time, stroking the plating under his hands. “Optimus. Please. Stop doing this to yourself. You did what was right for you, and that is what matters.”

“It was the only thing I could do,” said Optimus, very quietly. “We could not support a carrier. We could not support a sparkling, not in our current circumstances, and we could not afford to lose even one of our warriors to the demands of carrying. Strategically, I had to terminate. But that I felt such revulsion at the idea of carrying, not knowing whether it was because Megatron—” He stopped there, frame shuddering once.  “Strategically, it was necessary, but knowing that, it seems deeply selfish. My counterpart found it horrifying.”

A large, selfish part of Ratchet wanted to be angry that Optimus had not told him of this, but reason showed that Optimus’s silence only went to show how deeply private and painful those memories were. And his counterpart had had no compunction in invading those memories, turning them against their bearer as weapons.

The other Prime’s speech had not been directed at Ratchet. There was enough similarity between them that the other Prime could use only a few sentences to cause this deep devastation, open all Optimus’s fears and insecurities wide. 

“It’s all right,” he said again. “It was your choice to make.” That would not be enough; Optimus would still question himself, no matter how much right he had to make such a decision himself, without being accountable to Ratchet’s sentiments. “I would have done the same thing in your place.”

Something in Optimus’s frame relaxed at that. “Thank you, old friend,” he said, with relief flooding through his field. His arms tightened. “Thank you.”


	20. Chapter 20

Knockout insisted that Ratchet rest for another few hours before being released from the medical bay. Optimus took the time to put in a request for the use of the groundbridge; he wished to check in on _his_ Autobots, to make sure that things were still running smoothly in his absence.

It was denied. 

His request to use the bridge solely for the purpose of communication met a similar response. The refusals correlated neatly with the Vehicons who always seemed to be present, keeping a safe distance but watching him intently.

There was only one conclusion to be had; he and Ratchet were prisoners. Very politely kept prisoners, but prisoners all the same. 

He turned to look at his guards and they stepped back, visors flaring with alarm.

“I wish to speak to Megatron at his earliest convenience,” he said, shading his field with what courtesy he could find, with Ratchet so ill. 

One of the Vehicons bobbed his helm and left, transformed as soon as he was a polite distance away, and vanished off down the corridor. His counterpart shifted uneasily, his field drawn in so tight that Optimus was only aware of a vague sense of unease.

Optimus let out a long ventilation and looked down. He didn’t know what he could do; it pained him that the other mech was so intimidated, and below that was anger that such injustices had been wrought by his counterpart and so appended to his name. 

“I do not know what my counterpart may have done,” he said after a time, “but I regret its occurrence all the same. It is my sincere hope that he will never threaten another sentient being.”

The Vehicon’s visor flared bright again. “You’re a Prime,” he snapped. “You’re not supposed to care.”

Optimus glanced up at him, distress growing. The Vehicon took a step back, as if he expected to be struck. 

“Then tell me,” he said gently, “what a Prime is supposed to do.”

“The Prime is supposed to _be,_ ” said the Vehicon. “An outmoded position instated to keep the lower castes slaves. Untouchable. Tyrannical. The instrument of Primus’s will, no deed too foul not to enjoy Primus’s blessing.” His field flared with rage with each mention of Primus. 

After his counterpart’s presence in his own processor, Optimus could not find the response unreasonable; if that cold, pleased cruelty were truly manifestations of this Primus, it was all but reasonable

Having felt Primus’s presence, he found it hard to conceive of a connection between his counterpart and that serene comfort and acceptance. Even contemplating it made a great sadness well within him, that such a thing might be possible. It was deeply wrong, so deeply wrong it was easier to simply refuse to believe. 

“You have been grievously betrayed, then,” he said. 

“What, as if we’d _need_ a Prime in the first place?” said the Vehicon. “We have Megatron.” He raised a hand to his helm, listening to something. “And he wants to see you. Come on.” 

 

* * *

 

Megatron stood in the center of the bridge, hands clasped behind him, helm uptilted, and the position was so very reminiscent of Megatronus that Optimus’s spark hurt. He paused just within the door, looked around. 

The bridge was empty. 

“It hardly functions in its original capacity. Autobot sabotage—Arcee’s handiwork, as always. The auxiliary bridge suffices.” Megatron turned his helm, and Optimus’s ventilations caught, because the suspicious optic beneath the heavy optic ridge was blue. That optic ridge was blunt, what little he could see of the flares of color on the armor in the bad light, red instead of purple. 

Megatronus stood before him.

Optimus forced his field calm, took a step forward, could not find words.

Megatron turned to face him. There was the brand on his chest, red instead of purple, but the familiar shape shook Optimus back into the present. 

“You look like him,” said Megatron after a moment. “Orion. Not the thing he became.”

“You, too, greatly resemble the mech I called friend.” Optimus paused. “And teacher.”

“Yet your friendship met a similar end.”

“It did.”

Another long pause as they considered each other. 

“Thank you,” said Optimus at last. “For saving Ratchet.”

Megatron’s intake twisted, displaying flat dentae. “Words I thought I’d never hear,” he said, and there was a threat in it.

“I appreciate it greatly, especially in light of the losses you have sustained.”

Blue optics narrowed. “Who told you of that?” The voice was even, carefully controlled. The Megatron Optimus knew would have snarled. 

“Starscream,” said Optimus. 

Heavy ex-vent. “Of course.”

Optimus remained silent. 

“He tells me they had counterparts in your universe.”

“They do,” said Optimus.

“I take it they are well.”

Optimus inclined his helm in a nod, wary of the edge to Megatron’s voice. 

Megatron was silent another long moment. Then, “What is your business here, Prime?”

“I wish to contact my Autobots, to ensure that no ill has befallen them in my absence. My request has been denied; I had hoped that you might give me a reason for this measure.”

“I have very little reason to trust you,” said Megatron, “and if you are in fact a different mech than your counterpart, you will understand my reluctance to endanger my people’s lives on your mere assurances.”

“So we are indeed prisoners.”

“Rest assured, we will return you when your medic is able to tolerate the bridge. But I will not allow you to open a portal directly to the _Nemesis_ , so you may bring your Autobots aboard.”

Optimus bowed his helm. “I understand your concern,” he said. “But I fear for the safety of my Autobots and our human friends. They have proven themselves capable enough without me; it is Ratchet’s absence I find most worrying—the lack of a trained medic will cause great difficulty if there is an altercation.”

“Have you taken a long leave from them before, then?” said Megatron, and Optimus hesitated. 

Megatron picked up on that hesitation. “A painful subject, I gather,” he said. 

“Yes,” said Optimus. 

“Did you, too, lose your memory?” 

Optimus frowned at him. Megatron looked as unrepentant as his counterpart would have.

“Gathering information, Prime,” he said. “Necessary, however rude you find it.”

“I fail to see why that particular question is necessary, Megatron,” Optimus said. He fought the urge to allow his armor to flare defensively, the prickle of visceral unease growing in his tanks, as it had done every time he had confronted Megatron since his return from the _Nemesis_.

Megatron picked up on his field and shuttered his optics and for once, said nothing. 

“We will return you as soon as is possible,” he said at last. “Is there anything more?”

Optimus felt a chill over his armor but forced his pauldrons down into a neutral slant. “Yes,” he said. He had debated this long, but the knowledge of what had happened to this Jack and Miko would allow no other measure, no shrinking away from what was needed. Ratchet’s ill-treatment and the attitudes of the other Decepticons only enforced it. “I wish to extend an offer.” His misgivings about Megatron were poor excuse in the face of those. “If things go ill for you and your people, I would be willing to offer Rafael and any other humans associated with you asylum among my Autobots, along with any wounded.”

Megatron’s optics narrowed, the blunt optic ridges drawing down. “Only the helpless. You are as trusting as your counterpart.”

Optimus inclined his helm, though every instinct protested the gesture. “I too have my people to think of,” he said, “and I too, have little reason to trust you.”

The regard Megatron bent on him was deeply unsettling. 

“I can feel the sickness in your field,” he noted after a time. “You do not know how to deal with either of us off the battlefield.”

Honesty was all he had to respond to that. “I was more confident than I should have been in the past.”

“And I trust you far more when you are attempting to offline me.” Megatron’s mouth twisted. “Do you think I feel differently about you, Prime?”

Optimus looked at him and said nothing as he considered that. Megatron had kept his field unreadable throughout the conversation. But searching for it Optimus found a mirror of his own anger, sickened horror, distrust. Briefly, he wondered what his counterpart might have done to Megatron, what vicious wrongs had been perpetrated upon the leader of what his counterpart saw as an unholy defiance.

“My counterpart is capable of grievous harm,” he said at last. “That much I know from the cortical psychic patch. I know little else of this universe or your history with him, but I do not doubt the validity of your anger or distrust.”

“I cannot say the same; I have yet to meet my counterpart.” Was that vicious humor in Megatron’s field? Hard to tell. “And I am sorry to hear that you have had to suffer that; I too, know that invasion far too well.”

Optimus looked down.

When Megatron spoke again, it was with peculiar gentleness. 

“Perhaps we should begin again,” he said, “and each swear not to treat the other as he would his counterpart. Would that suit?”

“Yes,” said Optimus at last, “it would.”

 


	21. Chapter 21

No Optimus when he woke again, only Knockout fussing—and the degree to which Knockout could fuss was incredible. Drink this, lift that arm, let me scan _this_ , did you drink it yet, I said drink it, Primus take you.

Primus was said like a curse. 

He wondered how well Optimus was getting on, Optimus who looked askance every time Ratchet stamped the floor and directed curses at the ground beneath his pedes—if, Ratchet held, Primus was indeed omnipotent, He was astoundingly incompetent, and if He wasn’t then He was due an update on how life up top was just as slag as usual, thank You very much.

Optimus never commented on that. Optimus always claimed his unease was caused by Ratchet’s distress—faithful he might be, in a way Ratchet found incomprehensible, but he had a great horror of making that faith a source of discomfort to those under his command. He had seen too much of that within the Council and the military, earlier in the war, and discouraged it where he could. All mecha, he made it clear, were to be allowed to worship as they pleased—or not; Arcee and Bulkhead, for example, were both staunch atheists.

The crew of the _Nemesis_ seemed to be athiests in the most literal sense of the word, pronouncing _Primus_ as those in their home universe would say _Unicron_. Curiously enough, there was not a mention of Unicron, as if that god simply didn’t exist here. Unnerving enough to Ratchet, whose interest in theological matters was indifferent ranging to irate, undoubtably more unnerving still to Optimus.

Though if their counterparts were examples of particularly devout followers of Primus, Ratchet had every sympathy with the crew’s position.

Knockout followed him once he was released from sickbay, overprotective and bored. Optimus and Megatron, they were informed by the Vehicon sent to collect them, were on the bridge, the defunct bridge. Ratchet wondered what that meant, and settled for following the Vehicon without trying to make conversation. 

He hardly needed to _try._ Knockout made enough noise for the both of them, pestering the Vehicon about how his squad was doing, about the health of his trinemates, about the next movie night, all with a cheerful ease most unlike his counterpart. From the conversation, Ratchet gathered that Breakdown was still very much alive, though on detached assignment to one of the mines. 

They ran into Dreadwing halfway there, the big Seeker frowning viciously down at a datapad. He frowned still more when he saw Ratchet. 

“He’s smaller,” he said to Knockout, who shrugged. 

“Better this way,” he said. “Won’t startle people as badly.”

Dreadwing made an irritated noise and fell in with them. “He wants to see his bondmate, then?” 

“Yes,” said Ratchet, irritated both by being spoken of as if he weren’t there, and by the subtle sneer with which Dreadwing said  _bondmate_. “I do.”

“Good. I have things to discuss with our esteemed commander.”

They found Optimus and Megatron looking complacently down at a document, evidently pleased with themselves and unconcerned by the tension between the newcomers—this something of a feat as Dreadwing was making no effort to conceal the irritation of his field.

“Perfectly agreeable,” said Megatron as the doors slid shut. “It has been a pleasure to negotiate in good faith for once.”

“Indeed,” said Optimus. “A pity we cannot form something more permenant.”

“Not enough fuel,” said Megatron. “Universe-hopping takes unspeakable quantities of energon; you saw our energy consumption charts.”

Optimus nodded, looked up. “Ratchet,” he said, and smiled, the most genuine smile Ratchet had seen since before Unicron. 

“The hero of the hour returns,” drawled Megatron, heedless of Dreadwing’s grumble. He turned, kept his hands folded behind his back. “And how did you find our medical facilities, Doctor?”

Knockout shifted beside him, a madly hopeful look in the blue optics. Dreadwing’s attention turned to him as well. 

“Well staffed,” said Ratchet. 

Knockout grinned. 

“Good,” said Megatron, and Knockout puffed with pride. Dreadwing’s suspicious regard grew. “Knockout, is he able—”

“He should bridge just fine,” said Knockout, still preening. 

Optimus turned his attention back to Megatron. “Then it would seem we finished our work in good order. Ratchet and I ought to return as soon as possible.”

Something of the tension went out of Dreadwing’s frame. He stiffened again as if trying to hide it.

“Indeed,” said Megatron. “As enjoyable as your company has been, you have problems of your own to attend to. However, I have one request to make.”

“Which is?” 

“I would like to meet the human children I am to protect.”

* * *

 

Megatron in the base brought back bad memories for all concerned, but Optimus would not hear of unnecessarily subjecting a human to the inter-dimensional spacebridge before analyzing the readings to determine it was entirely safe.

So they met at a another location because it was indeed only right that Megatron meet the humans he was to protect. 

The Autobots were not happy about it. Dreadwing was not happy about Megatron going off alone in the company of Autobots, no matter what universe they were from. Agent Fowler— _both_ Agent Fowlers—hated the whole idea. 

Megatron and Miko were the ones who carried the situation, Megatron putting his pede down in no uncertain terms to Dreadwing ( _“You may accompany me, Dreadwing, but you are_ not _to take any weapons, do I make myself_ clear _?”_ ), Miko talking the other humans into it with shocking skill. 

“Compared to my parents?” she said, when Ratchet expressed his surprise, “Total cinch.”

And it was Miko who bounded out of the groundbridge and came to a halt at Megatron’s pedes, eyes wide. Bulkhead took two steps after her, hand outstretched. “Miko no—”

But the Decepticons didn’t move, just stared. Dreadwing looked shocked and perhaps a little sick, looked from Miko to Bulkhead and back again.

Megatron tried what appeared to be a gentle smile, which to Ratchet’s cynical optic looked severely out of place, and knelt to bring himself on a level with her. 

Agent Fowler had insisted on coming along too—as had his counterpart. They were now engaged in staring at each other, shock and something like disappointment on both faces. 

“Uh, hi,” said Jack with a wave. Raf just held onto his backpack and gulped. 

“It is good to see all of you well,” said Megatron, and while his voice was carefully even he looked away for a moment, quickly mastered strong emotion flashing through his field. 

The kids looked at each other, confused, but before anyone said anything unfortunate one of the Agent Fowlers spoke. 

“I thought you’d have a goatee.”

“Funny, I thought you would. You’re the one working with the Autobots, after all.”

Megatron was looking at the humans as if he couldn’t quite believe his own optics. Then he extended a hand and laid it on the ground, a nonthreatening gesture that invited examination.

Miko, ignoring Bulkhead’s protest, bounced over. “No claws?”

“No claws,” said Megatron, smiling again. “Though you are one to talk. I am accustomed to seeing you with green in your hair.” He gestured very carefully to a pigtail.

“Alternate me has _terrible_ taste,” said Miko and plopped herself down in the dirt in front of him. 

“She likely would have said the same of you,” said Megatron, and looked away. 

Miko put a hand on the only finger she could reach. “Hey. Sorry. Optimus wouldn’t say anything _clearly_ but uh…” her free hand came up to fidget with a pigtail, “We could hang out a bit if it’d help?”

Fuel consumption be slagged. Ratchet could all but _see_ the determination flicker through Megatron’s field. The old warlord smiled again, one edged with genuine sadness this time.

“I would like that.”


	22. Chapter 22

The base still burned.

The rumble of the Nemesis’s engines had long faded, but meticulous paranoia had kept the Holy Cause alive this long. 

He waited a day. Maybe two. Rotations were so short on this forsaken world. 

A hand thrust up out of the rubble, edged in blue light. An attentive listener would have heard the sibilant hiss of the Phase Shifter.

The Lord Prime rose from the rubble and flames.

He set his pedes upon solid ground and looked around. Grim satisfaction played through his field. Megatron thought him dead. The fool. His trust was in Primus, and He would preserve His servants and smite His enemies. Megatron was a fool to think he had escaped the holy justice of the god who had breathed life into his frame. Oh, the base might be lost, but Primus’s followers were still out there, still strong, and this little benighted world gave bountifully to those intelligent enough to take what was needed. 

Now to find Ratchet. 

Now for Primus’s final judgement upon Cybertron. 

Optimus Prime slid the Star Saber into its scabbard and turned his face to the dawn.

 


	23. Epilogue: Darkest Hour

He was semi-conscious when they found him. They didn’t let him stay that way for long. Sharp pain in an arm, injection, and he came into a hazy overbright awareness. 

Megatron stood in front of him.

The Insecticons carrying him dropped him. Couldn’t move, fell flat and felt a shattered windshield splinter. He bit back a sound of pain.

Megatron was there.

His Autobots would have found the information packages in their comm-suites by now, maybe even implemented them, maybe were safe even now. Instructions on the auxiliary groundbridge. Instructions on modification, on the emergency energon store. On what to tell that other Megatron.

He’d always insisted that Ratchet keep the locations of all of these things from him. 

This was why. 

Claws took him around the neck, lifted him. A blow, and another, battlemask torn from his face. He did not know if he cried out, only felt pain, the sticky heat of energon running down his faceplates. Audials fizzed static. 

Dropped, vicious kick. Other windshield shattered. Could not fight, limbs gave out, lifted again. Megatron snarling. 

Words. He fought to make them intelligible. 

“Where are your Autobots?”

He could feel the darkness rushing toward him, what he deserved. He had betrayed his very world, but Earth would be defended. He knew that other Megatron too well to think otherwise. 

“Safe,” he rasped. “Safe. You will never reach them.” 

He did not listen to the promises Megatron spat, did not listen to the jeers, sought the darkness, a surcease of pain. 

And something stopped him, something wrong. Was that Ratchet? And a voice that sounded like Megatron, was _not_ , yells and fire and he tried to make his optics online again. He reset them, he lost count of how many times, tried to push himself up and couldn’t. 

Hands on him, and he flinched, pain and fear together. 

“It’s all right, Optimus,” said Ratchet into his audial. “It’s all right. You’re safe.” An explosion, and Ratchet curled over him to shelter him. 

He still couldn’t see, flinched again as a great noise roared overhead, the whine of an overstressed bridge. 

“Megatron brought the _Nemesis_ ,” said Ratchet’s voice, and a cable pressed into his medical port, stasis protocols activated. “You’re safe. We found you in time. It’s nothing we can’t fix. Just stay still.” A click. “Soundwave, I need a groundbridge.”

Optimus sought for his bondmate’s hand, found it, clutched it as the world faded away.


End file.
